1. Field of Invention
This invention relates to rotary internal combustion engines and more particularly to a rotary engine in which at least a pair of pivotal wedges define the combustion chamber.
2. Prior Art
The concept of a rotary engine having rotating rather than reciprocating parts has long been of interest to engine designers. One of the continuing problems in the attempts to find a suitable rotary engine configuration is that of developing an acceptable structure for defining the combustion chamber or chambers of the engine. One approach has been to position one or more generally flat vanes in a rotor so that the vanes reciprocate in and out of the rotor as the rotor turns inside an outer casing. Fuel is introduced between the rotor and the casing and ignited to operate against the vanes and thereby cause the rotor to turn. See for example U.S. Pat. Nos. 1,354,189 and 2,345,651. One problem with these arrangements is that since the vanes receive most of the force produced by igniting the fuel, the vanes tend to rapidly wear and become deformed. Further, it is generally difficult to produce the desired compression of the fuel mixture prior to combustion.
One arrangement for improving the compression and combustion capability of rotary engines utilizing vanes is disclosed in U.S. Pat. No. 2,118,253. In this arrangement, the fuel mixture is compressed between two spaced apart, generally flat vanes disposed in a rotor body. The vanes are radially offset so that the rotor body receives a greater portion of the force of combustion than with arrangements in which the vanes are radially positioned. However, the vanes still receive a significant portion of the force of the combustion and, because of their generally flat configuration, tend to easily deform.
An arrangement utilizing a generally triangular-shaped vane or piston, rather than the flat-shaped vanes, is disclosed in U.S. Pat. No. 2,435,476. Each vane or piston of this arrangement operates independently of the other vanes and the compression of the fuel mixture is not obtained by any action of the vanes but rather the fuel mixture is compressed prior to injection into the combustion chambers. This latter feature increases the complexity and cost of the engine.
In the typical prior art rotary engine arrangement, many of the moving parts (for example the vanes) are mounted in the rotating member of the engine resulting in these parts being subject to significant centrifugal forces which increases the wear on such parts. Another common problem with the prior art arrangements arises from the need to lubricate the engine. In order for a lubricant to be applied to the rotating member of the engine, the lubricant must be supplied in some manner through the inside of the member; otherwise, the centrifugal force of the member will hamper the application of lubricant to it. However, even if the lubricant is provided through the inside of the rotating member, the centrifugal force tends to throw the lubricant from the rotating member causing inordinate lubricant losses. In current internal combustion engines, both rotary and reciprocating, the ignition of the fuel mixture is retarded so that the mixture is ignited some considerable period of time after the fuel mixture has been fully compressed and has been caused to subsequently expand by the movement of parts defining the combustion chambers. These arrangements have substantially reduced the thermodynamic efficiency of such engines.